#define  _CRT_SECURE_NO_WARNINGS
#include<stdio.h>

int My_Factorial(int x)
{
	while (x > 0)
	{
		return x * My_Factorial(x - 1);
	}
}

int main()
{
	int i = 0;
	scanf("%d", &i);
	int ret = My_Factorial(i);
	printf("%d\n", ret);
	return 0;
}


//------------------------------------------------------------

int My_Sum_Odd_number(int x)
{
	int i = 0;
	int j = 0;
	int sum1 = 0;
	int sum2 = 0;
	for ( i = 1; i <= x; i += 2)
	{
		sum2 = 0;
		for ( j = 1; j <= i; j+=2)
		{
			if (j % 2 != 0)
			{
				sum2 += j;
			}
		}
		sum1 += sum2;
	}
	return sum1;
}

int main()
{
	int n = 0;
	scanf("%d", &n);
	int ret = My_Sum_Odd_number(n);
	printf("%d\n", ret);
	return 0;
}